[Bassman79]

I recently put a set of 225/45/17 Blizzak WS80s on my M240i and have been playing with the tire pressure but have not been able to dial out the "wander" that seems to happen. The car sort of "swims" in the lane a little depending on my speed. I am running a square 17 setup. I'm accustomed to reduced steering feel when using winter tires but this wandering seems odd.

Would this be solely a tire pressure issue, or alignment/camber due to switching to a square 17 setup? I'm running about 36 psi all the way around right now. I initially ran higher pressures (tire shop set the pressure) and it was even worse. Any advice is appreciated. Thanks!

[aerobod]

In my experience WS80s will always squirm a lot on a RWD car with a decent amount of power, especially when new, due to the soft porous tread compound. X-Ice are a bit better, performance winter tyres such as LM60, PA4 or Sottozero 3 are a lot more stable.

[overcoil]

This is a total guess. I was looking at pics of your WS80 and it looks very squared shoulder style of tire. My Michelin’s seem much more round shouldered.

Searching the internet someone said square shoulder tires require more camber for stability. Which could explain the increased wandering you have.

I don’t know if any of the above is true but I had read some cars are designed to work better with either a square or round shoulder design.

The deep open tread design of a snow tire could mean the tires need some miles on them to tighten up the wandering feel - I don’t know if that actually works - be interesting to know if that is what will happen.

[Bassman79]

Thanks for the responses. Either I'm SOL and need to deal with squishy tires for a few months, or maybe playing with pressure more or getting the camber adjusted could help. I'll start with tire pressure and give them some time to wear in and see what happens. I will say that when i first had them installed from the tire shop the wandering was terrible - I could not even keep the car straight above 50 mph. They had the pressure above 40. Dropping the pressure to 35/36 helped a lot. Maybe i'll go a bit lower and see what happens.

[CanadianGatorBacon]

I've used my set of WS80s for 3 seasons. The wander gets better with wear. It hasn't completely vanished, which probably has to do with a combination of the issues already mentioned here, but it gets more manageable. I'll note that I stick to the BMW tire pressure recommendation of 33F/38R.

The few times I've needed them, the WS80s made me look like a snow champ in my rwd coupe compared to the unprepared fools around me. I love them for that. Still, those times are relatively rare given where I live and whether I "have" to drive in those conditions. I'm strongly considering a set of winter performance tires when my WS80s wear out.

[XutvJet]

Probably should have gone with the sportier PA4s given the lower snow amounts Denver sees. WS80s seem like overkill unless you're often driving in the mountains during snow events. I've got PA4s on my M235 in Kansas City (get about as much snow as you) and they don't wander. I do dislike the reduced and lighter steering feel, the lack of cornering traction when driving hard though, and greatly miss my aftermarket 18s. I need to move to somewhere that's warm during winter.

[Bassman79]

Xutvjet, I'll be doing some mountain driving, and I generally drive in to work unless it's really bad. But yes, probably would have been better to get other tires. I didn't realize how much softer these would be.

Canadian Gator Bacon, thanks for the tips, i'll try 33/38 and see what happens.

[///M Houbi]

Had similar issues ("wandering") with my PA4's.

I took delivery of the car with winterwheels mounted and the tyres where overinflated quite a bit. Acceleration was absolutely impossible above 100km/h and the car bounced from side to side very heavy.

Setting the recommended pressure and drive for a few hundred kilometers sorted it all out. Absolutely no more traction issues, no more wandering, no more bouncing.

[Shovelman]

Houbi
Yours sounds extreme, you may have had one or more beads not fully seated.

[Shovelman]

Interesting thread, explains some things.

This is my first BMW and I felt it floated all the time. Guessing that it is because ordinary cars are set up with a bit more toe in but BMW is set up straighter for better performance, albeit with a little more driver attention required.

Then I replaced my all season rear tires with Continental DWS 06 which are a little more capable in the snow, and they wander a bit. I think the taller tread at the outside edge flexes out and grabs a bit of outward traction causing the wander.

[Bassman79]

Originally Posted by Shovelman

Interesting thread, explains some things.

This is my first BMW and I felt it floated all the time. Guessing that it is because ordinary cars are set up with a bit more toe in but BMW is set up straighter for better performance, albeit with a little more driver attention required.

Then I replaced my all season rear tires with Continental DWS 06 which are a little more capable in the snow, and they wander a bit. I think the taller tread at the outside edge flexes out and grabs a bit of outward traction causing the wander.

Actually, i think BMWs (and many other sports/sporty cars) are set up with more toe-in, especially for the rear wheels, which is why the inside tread on the tires wears out more quickly. This is so that handling is sharper and the tire flattens out in corners and does not roll over. I'm not an expert and may be completely wrong, but that's always been my impression.

Either way, if you're experiencing wandering with summer or all-season tires, something may be up with your alignment or camber or the like. It may be worth getting checked out.

[dradernh]

Originally Posted by Bassman79

Actually, i think BMWs (and many other sports/sporty cars) are set up with more toe-in, especially for the rear wheels, which is why the inside tread on the tires wears out more quickly. This is so that handling is sharper and the tire flattens out in corners and does not roll over. I'm not an expert and may be completely wrong, but that's always been my impression.

I believe you're referring to (negative) camber, not toe.

[Bassman79]

Originally Posted by dradernh

I believe you're referring to (negative) camber, not toe.

Yes - thanks. That is what I meant.

[Sonertial]

Are your summer tyres RFTs? It's my belief that when these cars are set up for Run Flats, you want to be a bit careful switching them out - especially on to smaller rims.

I got this on my previous car (a 120D) when I installed winter tyres which were non-Run Flats. The wandering feeling was there but I got used to it, figuring that in winter it was of not much consequence. Grip was good, despite the uncomfortable feeling that the tyres were rolling off the rims.

When I tried the same thing with my summer tyres the next year, i.e. replaced them with non-Run Flats, I got the same effect. On summer wheels I could not accept this, the handling did not feel safe at all, I was slithering all over the road in corners, and on long sweeping curves the car balance could shift dangerously.

At a large cost I went back to new Run Flats. The wandering disappeared immediately, the car was much more planted.

On my current car I replaced the factory 18" Bridgestone Potenza s001 RFTs with 19" PSC2s with very good results, but that's to a larger rim and a very stiff, lower profile sidewall.

[Bassman79]

Originally Posted by Sonertial

Are your summer tyres RFTs? It's my belief that when these cars are set up for Run Flats, you want to be a bit careful switching them out - especially on to smaller rims.

I got this on my previous car (a 120D) when I installed winter tyres which were non-Run Flats. The wandering feeling was there but I got used to it, figuring that in winter it was of not much consequence. Grip was good, despite the uncomfortable feeling that the tyres were rolling off the rims.

When I tried the same thing with my summer tyres the next year, i.e. replaced them with non-Run Flats, I got the same effect. On summer wheels I could not accept this, the handling did not feel safe at all, I was slithering all over the road in corners, and on long sweeping curves the car balance could shift dangerously.

At a large cost I went back to new Run Flats. The wandering disappeared immediately, the car was much more planted.

On my current car I replaced the factory 18" Bridgestone Potenza s001 RFTs with 19" PSC2s with very good results, but that's to a larger rim and a very stiff, lower profile sidewall.

My regular tires are non-RFT Pilot Super Sports, running on stock wheels. I haven't any issues with the summer tires, thankfully.